chapman



(No Model.)

WID. CHAPMAN.

' BIRD GAGE SPRING.

No. 279,081. Patented June 5, 1883.

N. PETERS. mlwumo n lwr, Washington. \Zvv (1 UNITED STATES ATENT OFFICE. I

WILLIAM D. CHAPMAN, OF THERESA, NEW YORK, ASSIGNOR TO WV. D. CHAPMAN 8? SON, OF SAME PLACE.

BIRD-CAGE SPRING.

SPECIFICATION forming part of Letters Patent No. 279,081, dated June 5, 1883.

Application filed April 9, 1683. (No model.)

To all whom, it may concern:

Be it known that I, WVILLIAM D. CHAPMAN, of Theresa, in the county of Jefferson and State of New York, have invented certain new and useful Improvements in Bird-Gage Springs; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification, and in which Figure l is a side view of my improved birdcage spring. Fig. 2 is a similar view, showing the spring extended; and Fig. 3 is a sectional view, showing the manner of interlocking the free end of the bottom loop or hoop with the lowermost coil of the spring.

Similar letters of reference indicate corrc sponding parts in all the figures.

My invention has relation to springs to support bird-cages, hangingbaskets, or other light articles to which it is desired to give a vibra tory up-and-down motion; and it consists in the detailed construction of the spring, as will be hereinafter more fully described, and particularly pointed out in the claim.

My improved coil -spring is formed, like other springs of the same class, of a single piece of spring-wire, which may be either brass, steel, or any other suitable metal. At one end the wire is bent to form an oblong loop, A, after which it is bent at right angles, and the topmost coil, B, is formed around the free end of the loop A. The succeeding coils gradually increase in size, forming a swelled or ogee-shaped top part, C, after which the coils are again reduced gradually, so as to form a reduced section, D, near the lower end of the spring. The last coils, however, are again gradually increased in size, as shown at E,

and the lowermost coil, F, is bent to form a bottom loop or eye, G, the free end of which is filed to form a notch, H, which, by the spring or tension of the loop, will engage with or interlock with the lowermost spring-coil, F. In this manner I form a spring of an ogee shape, which is not only neat in appearance, but which, owing to its peculiar shape incident to its enlarged portion 0, reduced section D, and enlarged lower coils, E, has avariable tension, which will cause it to vibrate with less effort and for longer continuous periods than is the case with the spring-coils of this class as heretofore made.

The top loop, A, of the spring is attached to a spring-snap, (shown at 1,) by means of which the spring and the bird-cage or other article suspended from its lower end may readily be fastened to any suitable support.

Having thus described my invention, I claim and desire to secure by Letters Patent of the United States The improved bird-cage spring herein shown and described, consisting of a single piece of wire bent to form the top loop, A, a series of coils gradually increasing in size to form the swelled portion 0, followed by a series of coils gradually decreasing in size to form the reduced portion D, which again are followed by gradually-enlarged coils E, the lowermost one of which is bent to form the bottom loop, G, notched at H to adapt it to interlock with the lowermost coil of the device, substantially as and for the purpose set forth.

In testimony that I claim the foregoing as my own Ihave hereunto affixed my signature in presence of two witnesses.

IVILLIAM D. CHAPMAN.

\Vitnesses:

CHAS. P. HOLMES, DORMAN \VALRADT. 

